Aliens with latitude

Aliens with latitude

Top image: Around 30,000 cruise tourists visit Svalbard every year. One of the most popular landing sites is here in Magdalenefjorden on the nortwestern coast of Spitsbergen. Photo: Chris Ware.

New research shows that humans can unwittingly bring alien plant species to Svalbard. Increased travel activity and expected temperature increases over the next decades, may make the establishment of new plant species in the archipelago’s vulnerable ecosystem possible. This calls for a closer look at the management policy for travelling to Svalbard.

23 September 2011
Text: Eva Therese Jenssen/UNIS

Between 1995 and 2004 there was a 255% increase in the number of tourists visiting Svalbard, according to the Governor of Svalbard. During 2008, almost 69,000 travellers (locals, tourists and visiting scientists) arrived at the Longyearbyen airport. In addition, there is annually around 30,000 cruise ship passengers landing on Svalbard.

Today, there are 165 native plant species in Svalbard. Until recently there have been two processes that have maintained ecological integrity in the High-Arctic and Antarctic: low frequency of human presence and a cold climate. Now, both these processes are rapidly changing in Svalbard; an increase in human traffic and gradually warmer temperatures.

Scientists from the University Centre in Svalbard (UNIS), Tromsø University Museum and the Australian Antarctic Divison have now published the results from an experiment conducted in the summer of 2008 that shows that increased travel activity will lead to the introduction of alien plant species to Svalbard.

Free shoe-cleaning
In the summer of 2008 Chris Ware had an unusual offer for incoming flight passengers at the Longyearbyen airport. He offered free cleaning of their shoes. By scraping off soil of the soles of the shoes, collecting plant seeds from the soil samples and then planting them in a climate simulating the summer season in Svalbard, Ware wanted to find out whether alien plant species could be introduced and successfully established in the archipelago.

Samples from a total of 259 pairs of shoes were collected between June and September 2008. The travellers that participated also filled out a questionnaire about when they last had cleaned their shoes, whether the shoes had been in use in the three previous months and in that case, what type of environment (woods, alpine or city environment) they’d been used.

– A total of 1,019 from 53 plant species were found. Only two species were native Svalbard plants, the rest were plant species not known to Svalbard, says Chris Ware.

Cleaning shoes at Svalbard Airport

Chris Ware (left) cleaning shoes at Svalbard airport in July 2008. Photo: Eva Therese Jenssen/UNIS.

300,000 seeds annually
1,019 seeds divided by 259 pairs of shoes gives an average of 3,9 seeds per person.  If this average number is representative for the whole year, then up to 300,000 seeds could potentially arrive in Svalbard.

The collected seeds were planted in an environment of 10 degrees Celsius and 24 hours sunlight, simulating the average summer conditions in Svalbard. 10°C was chosen because it reflects the average summer soil temperatures recorded from a number of Svalbard sites.  The seeds were monitored for 48 days to see if they successfully germinated.

Twenty-six percent of the seeds (266 out of 1,019) germinated under the test conditions. Eighty-seven percent of them germinated within 14 days, the rest within 48 days, which is well within the growth season in Svalbard.

Focus on biosecurity
– This study demonstrates that people arriving in Svalbard pose an identifiable hazard to the local environment through the introduction of alien plant seeds that are capable of germination even under current climatic conditions, says Inger Greve Alsos who was the leader of this project.

– These findings can be an important contribution in a future discussion about a more conservative approach to regional biosecurity, so that the ecological and genetic integrity of the local flora is to be maintained, says Alsos.

Today there is no form of biosecurity policy at entry points to Svalbard, like those in place in New Zealand (Biosecurity New Zealand 2010) and for Antarctic tour operators (IAATO 2010).

The Governor of Svalbard and the Norwegian Polar Institute will soon write a management action plan in regards to non-indigenous plant species introduction to Svalbard, and maybe some time in the near future, travellers to Svalbard must pass through a cleaning process before they can walk out of the Longyearbyen airport and on to Svalbard soil.

The project received financial support from the Svalbard’s Environmental Protection Fund.

Reference:
Ware C, Bergstrøm DM, Müller E, Alsos IG (2011) Humans introduce viable seeds to the Arctic on footwear. Biological Invasions 13. DOI: 10.1007/s10530-011-0098-4

Related articles:
22.07.2008: Boot ’em up!

Barbarea vulgaris

Winter-cress (Barbarea vulgaris) is a non-native Svalbard plant which has been introduced to the Russian settlement Barentsburg. Photo: Bjørn Erik Sandbakk.

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